Clinical reports of cardiac function in patients with AIDS have recently been published. Additionally, cardiac dysfunction has been reported in patients who received high-dose interferon. The incidence and cause of cardiac dysfunction in patients with AIDS or HIV infection are unknown. In this study, noninvasive cardiac evaluation, including electrocardiogram, echocardiogram, and gated blood pool scan are done prior to drug therapy with AZT, interferon, or other anti-viral agents and repeated at 3 month intervals while the patients are receiving drug therapy. This study will provide important information about the frequency of cardiac dysfunction in HIV infected individuals as well as the potential for developing cardiac abnormalities while receiving antiretroviral therapy.